We illustrate the efficiency of implicit over explicit implementations.
We compare the tensor-free algorithm to explicit algorithms for REF , namely the explicit basic PGD, HOOI [1]}, quasi-Newton [2]}
and trust-region [3]}
methods.
For the last three algorithms, we use the code “tucker-als.m" in Tensor Toolbox [4]}, “symalgQNlc.m” in package [5]} and “lmlra3-rtr.m” in TensorLab [6]}, respectively.
HOOI and trust-region apply to general asymmetric tensors, because there do not exist variants just for symmetric tensors.
